New Scientist magazine says the Balcombe area of West Sussex could be one of the best places to drill for onshore oil after a study of shale rock throughout England.
The study’s leader, Alastair Fraser, of Imperial College London, told the magazine: “Our analysis highlights the Balcombe area in West Sussex as a sweet spot for shale oil”.
The richest shale formations found by the team were in the Kimmeridge Clay, which runs diagonally across southern England from Dorset to the east coast and is part of the geology of the Balcombe area. The researchers said the clay had an organic content of up to 20 per cent and was more than 500 metres thick in places. The potential yield is not yet known.
“The onshore shales are rich enough in organic material and have the right petrology for hydraulic fracturing,” Alistair Fraser told the magazine. “They’ve been buried to appropriate depths, exceeding 3 kilometres, and so fracking should work.”
Cuadrilla is currently applying for planning permission to flow test the oil well it drilled at Balcombe last year. In January, the company told residents it had drilled a horizontal well into the oil-bearing Micrite formation, a layer of limestone thought to be 33m thick. This is between two layers of Kimmeridge Clay. Cuadrilla said it would not need to carry out fracking because the Micrite was naturally fractured.
Some villagers were, however, suspicious of the statement. The Frack Free Balcombe Residents’ Association said Cuadrilla would have found it hard to keep the horizontal well in the micrite because of geological faulting. “Cuadrilla will have information not just on the micrite, but also on the shale layer”, it said.